1. Technical Field
The present invention relates to an image display medium and an image display device.
2. Related Art
There are conventionally known image display media that use colored particles as an image display medium, and with which repeated rewriting is possible.
Such image display media are configured, for example, to include a transparent dispersion medium 64 enclosed between a pair of substrates (a display substrate 60 and a back substrate 62), colored migration particles 66, and white particles 68, as shown in FIG. 13A and 13B. The migration particles 66 are distributed in the dispersion medium 64 and migrate between the substrates according to an electric field formed between the substrates. The white particles 68 are disposed densely between the substrates, and are of a size that is greater than that of the migration particles 66. The migration particles 66 migrate through the gaps between the white particles 68. Moreover, there are spacing members 70 provided between the substrates, in order to divide the space between the substrates into plural cells, so that particles are prevented from becoming unevenly disposed in specific regions of the substrates, or the like.
In such image display media, by applying a voltage between the pair of substrates, the enclosed migration particles are caused to migrate, and colored images are displayed according to the quantity of the migration particles which migrate and the color of the migration particles which migrate. When, for example, the migration particles are migrated to the display substrate side, as shown in FIG. 13A, the color of the migration particles may be observed from the display substrate side. When the migration particles are migrated to the back substrate side, as shown in FIG. 13B, since the migration particles are concealed by the white particles, the white of the white particles is displayed. Moreover, control of the magnitude of the movement of the target migration particles is performed by controlling the voltage applied between the substrates (the electric field strength formed between the substrates is controlled) according to the density of the target image. In this manner, images are displayed according to the density of the display images.